From publisher blurb:
Wield the Power Cosmic
Star Classes: Solarians is the first volume in our new series of class-focused player supplements expanding the possibilities the spacefaring classes of the Starfinder Roleplaying Game! Explore the mysteries of the stars with over 50 new rules and flavor elements for solarians, including origins, solar amplifications, revelations from 2nd to 20th level, zenith revelations, and the new Stellar Beacon archetype! Gear up with over a dozen new solarian weapon crystals like disruptive resonance crystals and blood-hungry feeder crystals and devastating weapon mods like adamantine infusion, radiant frequency, and lethal edge! Plus, you get 5 ready-to-use solarian characters and creatures from CR 2 to 15 like the void prophet and the dwarven celestial defender!